Description'Thoughts on Consensus': Four named contracts were grouped together under the heading “consensual contracts” in the Justinianic scheme of “obligations arising from contract”. These four contracts, sale, letting and hiring, partnership and mandate were classified as such because they could be created by consensus alone without any additional formalities prescribed by law. As a conceptual category, “consensual contracts” was not an invention of Justinianic law. As early as the second century C.E., the Institutes of Gaius, a textbook written for law students, grouped these four contracts together as obligations arising from consent and there have been suggestions that this scheme may have predated Gaius. The term consensus, the constitutive element underlying this group, is derived from the Latin verb, consentio –ire (3): to agree, accord. In the context of this group of contracts, the term signified agreement by the parties on a number of fundamental requirements set by law for each contract. But for all of the apparent simplicity of this account, some aspects of consensus remain unexplored. It is, for example, not yet settled whether a general notion of consensus underpinned all four of these contracts and what the scope or function of consensus was. This paper will attempt to address some of these questions.